Some transistors are used in circuits to provide bandgap voltage references and temperatures sensors. In bandgap references, a transistor is used to generate a constant voltage that is independent of temperature. Temperature sensor circuits use a voltage from a PN junction in a transistor to measure temperature. The temperature sensor circuits require voltage measurements on the transistors at different current densities. Because the gain, which is sometimes referred to as the beta values, may vary with current density, the bandgap and temperature sensor circuits may not be accurate. The problem is especially prevalent with ultra deep submicron CMOS (complimentary metal oxide semiconductor) transistors having low beta values.